Gearing for bicycles



(No Model.)

` W. J. PITZPATRICK.

GEARING ,POR BIGYGLBS. No. 401,425. Patented Apr. 16, l889.

` E. lll/111114011110' l; l

f, MM M /f MMI/e] UNITED STATES PATENT rricn.

IVILIIAM J. FITZPATRIOK, OF SOUTH BOSTON, MASSACHUSETTS.

GEARING FOR BICYGLES.

SPECIFICATION forming part of Letters Patent N o. 401,425, dated April 16, 1889.

Application led January 3l, 1889. Serial No. 298,207. KNO model.)

To @ZZ whom it may concern:

Be it known that I, WLLLIAM J'. Firzrnr- RICK, of South Boston, in the county of Suffolk and State of Massachusetts, a citizen of 5 the United Stat-es, have invented certain new and useful Improvements in Propulsion Gearing, of which the following is a specification.

My invention relates particularly to pedalgearing mechanism intended for use in that to class of vehicles-such as bicycles-wherein the wheel is caused to revolve by power ap* plied from the foot of the rider. Its object is yto produce a mechanism which shall contain a pedal-operated driving-gear and a driven gear fastened to and turning the bicyclewheel axle, whereby there shall be obtained the benefit of increased speed or power and also safety against the header motion of the vehicle, so called, around the axle of the zo driven wheel by reason of improvements in the construction and arrangement of the said gearing.

In the accompanying; drawings l have represented those portions of a bicycle wheel 2 5 axle, fork, and driving-gear necessary to illustrate my present improvement.

l Figure'l is a view in vertical section; Fig.

2, a side view in. sec-tion on the line x ot Fio.

l; and Figs. 3 to 6, inclusive, views of details 3o of the apparatus, as will be hereinafter more vfully explained.

In the drawings, A represents a portion of the axle of the bicyclewheel to be driven.

B represents a circular gear secured upon 3 5 the axle near its extremity and in a suitable manner, whereby rotation is imparted to the y axle.

O D represent an intermediate gear, a portion, O, of which meshes with the axle-gear B, and the other portion, D, of which meshes internally with the drivin g-gear E, which is it.- self turned by powerderived from the pedah arm F.

All of the mechanism heretofore described is located in a shell or recess formed at the lower part of the fork G of the vehicle.

'The preferred ratio of the gears above menn tioned and that shown in the drawings is as follows: The gears B and D are ot' the same 5o size, and the driving-gear C is to each of them as two to one. The gear E is to the gear D as three to one. It follows from this that a third of a revolution of E produces one revolution of D and also of C, they being connected together, and one revolution of C produces two revolutions of the anle-gear, and consequently of the bicycle-wheel.

Each of the gears before described may be provided with ball-bearings, and they are so represented. The gear B has a single row of balls t-urning in a grooved bearingin the shell at e. The gears C D have a double row of balls turning upon a stud, 1I, which is attached to the shell in any convenient manner.

The gear E has a single external row' of Y 65 balls turning in grooves formed in circular nuts b c, also located in the shell of the fork, as shown. Furthermore, the shaft f of the" pedal F has a double row of ball-bearings located within aboX, i, formed within the cir- 7o cular plate I, which covers and incloses 'the shell. Any suitable mechanism may be eni ployed in connection with the gear E, andthe ordinary pedalarm of a bicycle, whereby' power applied. to the pedal-arm shall cause the gear E, with its connected pedal-gearing,r to revolve. I prefer, however, to employ for this purpose the locking and releasing connection, which I will now proceed to describe.

Upon the inner end of the shaft f of the` pedal-arm F is secured an arm, g, to which at its lower portion is attached (see Fig. l) a pawl-gear, J. For a convenient means of attaching this gear to the arm I form its lower portion in a fork, as shown. The shaft 8 5 of the gear .I works in slots j in the fork of the arm g. Two stops, K K, placed upon the platel at a distance apart equal to Onethird of the circumference of the gear E, come within the path of aV projection, g', upon the arm g (shown in Fig. l) and limit its motion, and consequently the motion of the pedahto the are of which the stops represent the eX- tremities, Upon the arm g is also a lockingpin, L, (see Fig. of a width sufficient to it 95 between two of the teeth on the pawl-gear J, and thus lock it to the arm g, and thereby convert the gear while locked into a pawl.

The mechanism thus far described operates as follows; The pedal-arm F being sup- Ico posed to be at its highest point, if downward pressure be applied to it, this locks the arm g into the gear J, thus converting it into a pawl, and the continued descent of the pedalarm F, acting through this pawl, drives the gear E around until the arm g strikes the lower stop K. This amount of revolution of `the gear E, by reason of the ratio of the gears,

as before explained, produces two revolutions of the axle of the bicycle.

The return of the pedal to its highest point may be accomplished by a coiled spring, M, (see Fig. 6,) in the ordinary manner, having its fixed end fast to the plate I and its free end to the shaft f. I prefer, however, to employ mechanism whereby the pedal shall be positively returned by the revolution of the intermediate gear, C, which mechanism I will now proceed to describe.

I'lprovide upon the inner extremity of the shaft f a projection, f', (see Fig. 4,)-having a portion cut away in an arc of a circle, as shown, `and upon the side of the gear C, I provide a single tooth or wiper, N. (See Fig. 3.) The projection f is so located upon the ex-y tremity of the shaft f that when the pedal is in its lowest position a portion-of the proj ection f shall lie within the path of the wiper N. YVhen, therefore, the gear C revolves,this wiper, being brought in contact with the cornerA of. the..projection f', turns the shaft f back until the pedal Fis restored to its highest position. T he operation of this portion of the machine can be best seen at Fig. V2.

It should be observed that the slotted connection between the fork of the arm g and the paWl-gear J is for the Apurpose of lallowing sufficient play between the arm g and the pawl-gear J that when the pedal-arm is descending the pin may enter and lock the gear; butin the reverse motion-when the pedal-arm is ascending-the gear may move slightly backward,so'as to turn freely and clear of the locking-pin L.

By reason of the mechanism hereinbefore described. it will also be seen that header motion-that is to say, motion of the fork and the tendency of the fork and its connected parts is to -move around the axle A as a center.` This will produce a reverse motion in the gears C D, and consequently in the gear E.- Should this occur when the pedal-arm F is vat its highest point, the motion of the fork around the axle will be at once checked, because vthe upper stopv K will engage with the projection g. Thisprevents further upward motion of the arm g, and therefore further j reverse or upward motion of the pawl-gear J,

because it locks with the locking-pin L, and, since the pawl-gear J, being locked, cannot turn, the gear E and its connected gears are prevented from turning, and thus the header motion is checked.

As there is, of course, in a bicycle a duplication of these parts-viz., one set for each pedal-one or the other of the pedal-arms can never be farther from the upper stop K than one-half of the total arc of reciprocation, or one-sixth of the circumference of the gear E. Should the bicycle strike the obstacle when the arms are in this position, the reverse motion of the gear C will continue until the proj ection g brings up against the stop K on one side or the other, when a stopping of the reverse motion of the gearing will take place, as before. At the same time it will be obvious that the downward pressure of the rider upon the time will also tend to hold the'gear E, and

consequently the rest of the gearing, against reverse motion, and this pressure may be suficient ofV itself to check the reverse or header motion. When this motion is checked, the main wheel of the bicycle, if the obstacle is not of too great height, will climb or jump over it like a wheel-barrow, but no'header motion can takeplace. i

I have hereinbefore described a certain preferred ratio of the gearing, and in connection with that ratio acertain specificr position of the stops K*-viz., at the ends of an' arc equal to one-third of the circumference ofthe driving-gear. I have selected this specific ratio becauseI believe it to be in practice the most desirable. other ratios of gearing `may be adopted, and if the ratio be changed it may-be necessary, where a reciprocating motion is given to the pedal, to increase or decrease its range'of motion beyond that hereinbefore set forth.

l. In combination, the internal drivin ggear, D, the pedal-arm land its shaft, an arm,g, also att-ached to and operated by said shaft, apawlgear, J, having its bearings in slots in the said arm g and meshing with the drivingfgear, and a locking-pin, L, attached tothe said arm and adapted to enter the tooth of the pawl-gear to lock the same. Y

2. In combination, the internal driving-gear, D,the pedal-arm and its shaft, an arm, g, also attached to and operated by said shaft, a-pawlgear, J 3 having its bearings in slots'in the said arm g and meshing with the driving-gear, a locking-pin, L, attached to the said arm' and adapt-ed to enter the tooth of thel pawl-gear to lock the same, and stops K K, located upon an adjacent portion of the fork or non-revolving part of the device and adapted to engage with a portion of the arm g to stop its motion and j pedal-arm F,'with its shaft f, having an arcshaped projection, f ,formed thereon, and the' gear C, having the projection N, adapted to I think it obvious, however, that IOO IIO

strike against the said projection f to return In testimony whereof I have hereunto subthe pedal-arm to its upper position. scribed my name this 19th day of January,

4. In combination with the fork G, the cover- A. D. 1889. plate I, adapted t0 be attached thereto, the WILLIAM J. FITZPATRICK. 5 said plate being provided with stops K K, for Witnesses:

the purpose set forth, and also with a hex, fi, JOHN II. TAYLOR, to form a bearing' for the pedal-arm shaft. ELLEN B. TOMLINSON. 

